Experimental study on heat release characteristics of thermochemical heat storage considering various operating parameters

Thermochemical heat storage is a promising energy storage method and has received much attention in recent years. To improve the design and application of such systems, a better understanding of the characteristics of thermochemical heat storage is required. In this study, we analyze the heat release characteristics of thermochemical heat storage considering various operating parameters, such as charging temperature, humidity, and material. Three different thermochemical materials are considered herein, namely, zeolite 13X, zeolite 5A, and silica gel. The temperature profile at the inlet and outlet of the storage chamber, and that inside the chamber packed with thermochemical material, were measured. The pressure drop across the chamber was measured as well. The results indicate that the heat release characteristics change with position and time. Furthermore, the temporal curves of released heat are significantly affected by charging temperature and humidity. Zeolite 13X rapidly released a large amount of heat within a short period of time, whereas silica gel gradually released a small amount of heat, over a longer duration of time. The pressure drop across the chamber was found to vary with the bead size of the thermochemical material. Thus, the operating parameters including charging temperature, humidity, and material, have a significant effect on the characteristics of heat release. The data obtained herein can serve as a reference for the design of thermochemical storage systems.